Electrical plug connection



March 29, 1949. F, M, BANNER 2,465,517

ELECTRICAL PLUG CONNECTION Filed Aug. 17, 1946 INVENTOR.

FRANK DANNER AT TURNEY Patented Mar. 29, 1949 UNITED STATES FTENT OFFICE 1 Claim.

This invention relates to an improved electrical plug connection for attachment to electric sockets and the like. An object of the present invention is to provide an improved electric plug that can be quickly inserted into a specially formed connection and which will be retained therein in a manner that will never fail in preventing accidental displacement or removal of the plug while in service.

Another object of the present invention is the provision of a specially formed threaded shell that is capable of being connected to a conventional wall or lamp socket or the like and to provide a specially constructed plug that is capable of being directly inserted into the said shell and positively retained therein.

A further object of the present invention is to provide the plug with a tube and to provide a coil spring within the same forming an electric conductor therein and to further provide a second electric conductor and fix the same into the outer periphery of the said tube, the said second conductor being equipped with resilient means which will positively prevent the plug from being accidentally pulled out of the socket.

A still further object of the present invention is to provide an electrical plug of the character described that is durable, simple in construction, economical to manufacture and highly efficient and serviceable in use.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawin forming a part of the specification, and wherein for the purpose of illustration like numerals designate like parts throughout the same,

Fig. 1 is a central longitudinal sectional view of the improved device illustrating the complete assembly and arrangement of the various parts,

Fig. 2 is an end view of the device looking in direction of the arrow 2 in Fig. 1,

Fig. 3 is an end view of a specially constructed threaded shell employed in the invention,

Fig. 4 is an end sectional View taken through line 44 of Fig. 1, looking in direction of the arrows,

Fig. 5 is a side elevational View of the tubular plug that projects into the said shell and also showing a portion of the coil spring and a metal band that is associated therewith,

Fig. 6 is an end elevational view of the tubular P Fig. '7 is a central vertical longitudinal view of the tubular plug, and

Fig. 8 is a view of the metal band secured to the plug.

Referring in detail to the drawings and to the numerals thereof, the numeral 9 designates a shell made of any suitable electric insulation material and is equipped with a conventional electrical plug threaded metal covering I0, which covering overlaps the inner end of the shell forming a metal wall as illustrated to advantage at H in Fig. l. The said shell is formed with a circular passageway l2 and a pair of oppositely opposed slots It as shown in Figs. 1 and 3.

A tubular plug it formed of a suitable electric insulation material slidably fits into the said passageway l2 of the shell and extends therethrough as shown in Fig. 1 and is formed with an enlarged base portion it that closes against the outer end of the shell as indicated at I6. The said base portion [5 is formed with oppositely opposed recesses I! and it into which a pair of binding screws 59 and 20 are respectively positioned. An electric conductor 2! leads from the screw l9 through a suitable aperture l9 and a second conductor 22 leads from the screw 26, through a second aperture 29', designatin the conductors of a conventional electric cord or other circuit, an opening 23 being formed in the base l5 for accommodating the said cord. Each of the said conductors are properly insulated but have bared end portions for electrically contacting their respective screws. A small metal coil spring 24 leads from the binding screw 20 and extends through the passageway I4 of the plug [4 and rests on the seat 24 therein and provides an electric conductor and also a resilient contact member for engaging the electrical end connection in a conventional socket not shown, it being obvious that the invention is used with any standard type of electric socket Well known in the art. A suitable wire 25 leads from the binding screw l9 through the groove 25 to a metal band 26, which band is formed with outwardly flaring transverse projections 2'! that fit tightly against the metal surface ii at the inner extremity of the shell 6 as shown to advantage in Fig. 1. Electrical contact is thus made with the outer metal wall of the shell. A circular groove 28 is provided in the outer periphery of the plug for receiving and supporting the said metal band 26, which band is preferably made of two suitable lengths of wire properly fixed together and tightly secured in the circular groove 28, the twisted ends forming the projections 21. The said band can be constructed of a solid piece of Spring metal if desired and split similar to a piston ring, whereby it will 3 open sufliciently to pass over the end portion of the tube and resiliently close in the circular groove. The said projections 21 may angularly extend from the outer periphery of the plug or are beveled as indicated at 29 to facilitate fastening of the plug to the shell.

From the foregoing description taken in conjunction with the accompanying drawing it will be readily observed that the plug is assembled into the shell by inserting the resilient projections 21 into the oppositely opposed slots l3 and moving the said plug through the shell and then turning the plug either to the right or to the left, whereby the projections 2! will tightly fit against the inner metal wall I I of the shell, locking the members together. It is obvious that this type of electrical plug cannot be accidentally removed from the socket and will never fail in keeping the contacts closed for preventing the electric cord from getting disconnected.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same and that various changes relative to the shape, size, material and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claim.

Having thus described my invention, I claim:

In combination with an electric socket, an electric plug connection comprising a cylindrical shell made of electric insulation material, a threaded metal cover fixed around the outer periphery of the shell and overlapping the inner end of the same and capable of being threadedly secured into the said socket, an insulating tubular plug slidably positioned in the said shell and extending therethrough, an elongated coil spring forming an electric conductor within the tubular plug and capable of extending through the said shell and resiliently contacting the said socket, a second electric conductor extending through the said shell, a circumferential groove formed in the outer periphery of the plug in proximity to the inner end of the shell, a metal band having contact With the second mentioned conductor secured in the said circumferential groove, the said metal band being formed of two sections of wire having their end portions twisted together tightly securing the band in the groove and forming outwardly extending projections that tightly abut the overlapping metal surface at the end of the shell for retaining the plug in the shell, and a pair of oppositely opposed slots longitudinally extending through the inner periphery of the shell for receiving the said projections, Whereby the plug can be removed from the shell.

1 FRANK M. DANNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,022,815 Benjamin Apr. 9, 1912 1,878,247 Beck Sept. 20,1932 1,996,410 Edwards Apr. 2, 1935 2,104,945 Guinn Jan. 11, 1938 2,303, 17 1 Jochum et al Dec. 1, 1942 2,393,485 Still et al Jan. 22, 1946 

